In the field of wireless communications, cognitive radio is viewed as a novel approach for improving the utilization of a precious natural resource, the radio electromagnetic spectrum.
The cognitive radio, built on a software-defined radio, is defined as an intelligent wireless communication system that is aware of its environment and uses the methodology of understanding-by-building to learn from the environment and adapt to statistical variations in the input stimuli, with two primary objectives in mind, namely highly reliable communication whenever and wherever needed, and efficient utilization of the radio spectrum.
Attaining these objectives in cognitive radio may therefore involve controlling communication equipment in such a manner as to provide reliable communications while reducing adverse effects on other communication equipment. Conventional communication techniques, however, typically exploit available communication resources for the benefit of particular communication equipment, one particular user for instance, without substantial consideration of impact on other communication equipment.